Background Robot-assisted laparoscopic surgery has several advantages over conventional laparoscopy. However, population-based comparative studies for low anterior resection are limited. This article aimed to compare peri-operative results of robot-assisted low anterior resection (RALAR) and laparoscopy Methods This retrospective cohort study used data from patients treated with RALAR or conventional laparoscopic low anterior resection (CLLAR) between October 2018 and December 2019, as recorded in the Japanese National Clinical Database, a data set registering clinical information, perioperative outcomes, and mortality. Of note, the registry does not include information on the tumour location (centimetres from the anal verge) and diverting stoma creation. Perioperative outcomes, including rate of conversion to open surgery, were compared between RALAR and CLLAR groups. Confounding factors were adjusted for using propensity score matching. Results Of 21 415 patients treated during the study interval, 20 220 were reviewed. Two homogeneous groups of 2843 patients were created by propensity score matching. The conversion rate to open surgery was significantly lower in the RALAR group than in the CLLAR group (0.7 versus 2.0 per cent; P < 0.001). The RALAR group had a longer operating time (median: 352 versus 283 min; P < 0.001), less intraoperative blood loss (15 versus 20 ml; P < 0.001), a lower in-hospital mortality rate (0.1 versus 0.5 per cent; P = 0.007), and a shorter postoperative hospital stay (median: 13 versus 14 days; P < 0.001) compared with the CLLAR group. The CLLAR group had a lower rate of readmission within 30 days (2.4 versus 3.3 per cent; P = 0.045). Conclusion These data highlight the reduced conversion rate, in-hospital mortality rate, intraoperative blood loss, and length of postoperative hospital stay for rectal cancer surgery in patients treated using robot-assisted laparoscopic surgery compared with laparoscopic low anterior resection.

Abstract. The suppressors of cytokine signaling (SOCS) family inhibits not only Janus kinase (JAK)/signal transducers and activators of transcription (STAT) but also focal adhesion kinase (FAK) signaling pathways, and has tumor suppressor activity. Aberrant methylation in the promoter region of the SOCS3 gene frequently occurs in several types of human malignancy, and its transcriptional silencing is associated with malignant tumor behavior. In malignant melanomas, the expression and methylation status of the SOCS3 gene have not been elucidated. We therefore examined the methylation status and/or protein expression of the SOCS3 gene in 5 human malignant melanoma cell lines, 2 primary cultures of normal melanocytes, and surgically resected tumors (5 malignant melanomas and 2 melanocytic nevi). Four of the 5 melanoma cell lines and the 2 primary cultures of normal melanocytes expressed SOCS3 protein to various degrees, and only one melanoma cell line was negative. Expression of SOCS3 protein was inversely correlated with methylation status in the SOCS3 promoter region, and treatment with a demethylating agent (5-aza-2'-deoxycytidine) was able to induce expression of the protein in one melanoma cell line that was SOCS3-negative and another that was weakly positive. Three of the 5 primary malignant melanomas and one of the 2 melanocytic nevi showed aberrant methylation. These results suggest that inactivation of the SOCS3 gene by hypermethylation may be involved in the promotion of malignant behavior of melanomas.

Most esophageal carcinosarcomas are diagnosed as so-called carcinosarcoma, in which individual elements may be derived from a single common ancestor cell, and there have been a few reports describing true carcinosarcoma originating from two individual stem cells. We describe a case of esophageal carcinosarcoma exhibiting neoplastic osteoid formation. Immunoreactivity for vimentin and p53 was limited to only the sarcomatous component and was absent in the carcinomatous component. Furthermore, a point mutation in exon 7 of the p53 gene was observed only in the sarcomatous component. Both sarcoma and carcinoma cells distinctively metastasized to different lymph nodes. These observations led us to diagnose the esophageal tumor as a true carcinosarcoma.

PurposeLaparoscopy-assisted colectomy (LAC) has gained acceptance for the treatment of colorectal cancer. However, conventional palpation of the liver and adequate observation of the abdominal cavity are not achievable during LAC. The aim of this study was to assess the clinical value of using Sonazoid (contrast enhanced)-intraoperative laparoscopic ultrasonography (S-IOLUS) in patients with primary colorectal cancer.MethodsFrom May 2005 to August 2008, 454 patients underwent 339 LACs and 115 open colectomies for colorectal cancer. One hundred forty-eight patients with clinical stage II or III colorectal cancer, as determined by preoperative imaging, who were undergoing LACs were prospectively enrolled.ResultsAlthough IOLUS did not detect any lesions, small hypoechoic lesions were detected by the S-IOLUS (n = 71) in the Kupffer-phase view of two patients (2.8 %). None of the 71 patients who underwent S-IOLUS showed liver metastases within 6 months after LAC. In the conventional IOLUS group (n = 77), metastatic lesions were identified in two patients (2.6 %). The new liver metastases in these two patients were detected within 6 months after LAC.ConclusionsS-IOLUS of the liver during colorectal cancer surgery is useful for staging and as a diagnostic modality. It can identify lesions that are undetectable by preoperative imaging, and may be considered for routine use during LAC.

Leiomyomas are the most common benign tumors of the esophagus. They usually occur as a single lesion or as two or three nodules. Only two cases of esophageal multiple leiomyomas comprising more than 10 nodules have been reported previously. Moreover, there have been few reports of esophageal squamous cell carcinoma overlying submucosal tumors. We describe a 71-year-old man who was diagnosed as having a superficial esophageal cancer coexisting with two or three leiomyoma nodules. During surgery, 10 or more nodules that had not been evident preoperatively were palpable in the submucosal and muscular layers throughout the esophagus. As intramural metastasis of the esophageal cancer was suspected, we considered additional lymphadenectomy, but had to rule out this option because of the patient's severe anoxemia. Microscopic examination revealed that all the nodules were leiomyomas (20 lesions, up to 3 cm in diameter), and that invasion of the carcinoma cells was limited to the submucosal layer overlying a relatively large leiomyoma. This is the first report of superficial esophageal cancer coexisting with numerous solitary leiomyomas. Multiple minute leiomyomas are often misdiagnosed as intramural metastasis, and a leiomyoma at the base of a carcinoma lesion can also be misdiagnosed as tumor invasion. The present case shows that accurate diagnosis is required for the management of patients with coexisting superficial esophageal cancer and multiple leiomyomas.